Improvement in goal-boeing bit



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Be it known that' I, SAMUEL GIssINeER, of 'the-. city andcountyofAllegheny, in the Stateof Pennsylvania, have invented a new and usefulImprovement inBoring-Bits for Coal-Mining Machines; and I do hereby A"declare the following to he a full and exactdescription.thero-referenee being had'to the accompanying draw# 'ingsand to the letters and ig'uresiof reference markedtlnsreon-l The natureof my invention consistsinv providin'gthe boringfbits of coal-miningmachines with an entering and centring-point, scoringand-euttingpoints,and a guide, and s o arranging thebits ou`theboring-shafts of the 'mining-machine that they will cut out a gaporspace between the'bits, and thereby forming one bearingin .To enableothers skilledin the artto make and use myinventioml'will proceedtodescribe its construe-v tionand operation. ,-f Y

vIn the accompanying drawings, which fornipart of my speciclatiOn, arepresents the frame for the boring- `shafts 1, 2, andS, which may berevolved andfmoved forward byfany known mechanism. To the forward endsofthe shafts 1,2, and 3, I secure the boringbits A, which are providedwith entering or centring-points B,

.cutting and scoring-points c andf. The portion d f the bit between',the cutting-pontsfand e acts as a guide for the bit, causing it to cuton a true line wit-h the plane of itsshaft, thereby vpreventing allundue strain on the bit-shaft.,` 'I he boring-.bits are made from' ilatbars of steel, and are arranged alternately on the shafts 1, 2, fand3,in'the mannershown in the drawings. l v

The operation of my invention is as follows: Motion is imparted tothesh'afts'l, 2, and 3, so that each shaft 'moves at the same speed. Theshafts are made to move forward by any known -mechanism. The pointsBveut litl-:reir way in'tqthe coal, and will steady or act as acentre-point'for the euttersf, which cut, score, or Ichip out their wayinto the coal, and the points B and f, and the part marked d, willact-as a centre or guide for the cuttingpointse, which will cut, score,or chip their way into the coal.V i v By making the bitsin .the formrepresented in the drawings, and arranging them on the shaftsjn the'manner described and represented, the bits will score or chipone-continuous bearing-in" cavity for breaking down the coal, said cavity being always made truc and on the line desired.

The eiiect produced by my improvement in bits for coal-mining whichdistinguishes them from other boring-bits of such machines, consists inchipping or scoring lout of the coal, instead of a drilling process.

AThis chipping or scoring process is produced by the recesses marked s.The points B, e, andf, cut their way intothe coal,and that portion ofthe coal which comes into the recessess is broken or chipped off andthrown out by the revolving of the bits'. I

The form of my improved bits will in every case prevent the tendency ofthe bits from travelling out of a direct line. It is a fact well knownto those skilled iu the art of' mning coal -that one of the greatobstacles in bearing-in or undermining is the di'erence in theformations lfound in the bed of coal. At one point it is hard, at otherpoints it is soft, and this difference in the bed of coal causes theordinary boring' bits to travel out of a direct line. I overcome thesediculties and obstacles by the use ofthe boring-bits herein describedand represented.

Having thus described the nature, construction, and operation of myimprovement, what .I- claim as of my invention, is-

The bit or cutter A, providedwith the entering-pointB, scoring andcutting-points e and f, and guide d,

substantially as herein describedeand for the purposes set forth. i vSAMUEL GISSINGER.

Witnesses:

.Twas J. JonNsroN, ALEXANDER I Imzs.l

